Method of treating crimped synthetic yarn for use in the lace industry



United States Patent METHOD OF TREATING CRIMTED SYNTHETIC 6 Claims. (Cl. 51-157 France, assignor to W'oonsocket, R.I., a corporation The production of crimped yarns made from continuous filaments of nylon, for example, is well known in the textile industry, apparatus and methods therefor being disclosed in United States patents of which Patents Nos. 2,734,252 of February 14, 1956, and 2,740,992 of April 10, 1956, in-the name of Ewart H. Shattuck are examples.

Such yarns are made from individual continuous filaments, the number and denier measurements of which vary to produce yarns of various weights and sizes. In their initial or filament yarn state, such yarns have in them no more twist than unavoidably occurs in their production and for practical purposes are free or substantially free of twist.

In this state, because of their bulk and looseness the crimped yarns are incapable of use on lace weaving looms of the Leavers and go-through types in the lace industry. Such looms are well known in the trade and are describedand illustrated, for example, in the Hand Book entitled Leavers Lace and edited and published by American Lace Manufacturers Association Inc, January 1949. The Leavers machine fundamentally embodies the principle of the Heathcoat bobbinet machine, the essential difference being that all the carriages are placed in one tier, with one fixed, constant motion in one gait instead of traversing the machine. This dilference in operating the carriages makes the production of fancy lace possible. One of the more recent improvements on the Leavers machine is known as the go-through principle. In a machine so equipped landing bars are dis carded. Instead, the machine carries the bobbin threads twice through the warp threads at one revolution of the crankshaft, considerably increasing the working speed. It is obvious that twisting will alter the yarn in respect to their bulk and looseness, but it is a fact, of course, that twisting causes a decrease in length and a resultant increase in bulk or thickness of the yarn.

With a' given amount of twisting, that is, the introduc' tion of a given number of turns per unit of length of the.

yarn, the alterations in these, relative dimensions will vary with different yarns depending upon the number and weight or denier measurement of the component filaments of the yarn. The desired results, therefore, cannot be attained by haphazard or indiscriminate twisting.

The desired characteristics of the yarn for use in the lace industry differ appreciably with difierent types of lace, a fact which definitely has to be taken into account in determining the treatment to be given to the crimped filament yarn.

It is, therefore, one of the objects of this invention to provide a formula or rule by which to determine and regulate the degree of twist to be given to crimped filament yarns of all commercial weights and numbers of filaments to adapt the yarns for use on lace weaving looms for the production of various types of lace.

It is another object of the invention to provide an improved sizing for the yarn which will give to the yarn the properties necessary for eflicient use in the lace in- 'ice dustry, and will preserve the yarn from contamination with graphite during the weaving operation.

Other objects and advantages of the invention will appear from the following particular description of representative operations on filament yarns in accordance with i the method of the invention.

Fundamentally, as contemplated by this invention, it has been found that for the obtaining of the desired properties of the crimped yarn for use in the lace industry, the amount of twist imparted to the crimped filament yarn will vary according to the characteristics of the yarn and according to the type of lace into which the yarn is to be woven. It has been found that the number of twists must vary in inverse relation to the weight or denier measurement of the yarn and, to the number and consequently to the denier measurement of thecomponcut filaments of the yarn. ,For different types of lace, the proportionality of this inverse relation will vary some what, but it has been found that for the various types of lace the number of turns per meter will range approximately from 2 to 4 times the denier measurement for the heavier yarns to from 6 to 10 times the denier measurement for the lighter yarns.

Exemplifying the yarns used in making the various types of lace are those known as voilines, mi-perles or organsins and ovales or fioches.

Voilines are continuous, single-strand yarns with a low twist either to the right or left. For voilines, starting with crimped filament yarn having no more than the producers twist, it has been found that, depending upon the weight of the yarn and number of component filaments the twists given the yarn for the best resultsare representedby the following:

Voilines 40 d.--13 filaments480 turns (right or left) per meter 70 d.--34 filaments-400 turns (right or left) per meter d.34 filaments340 turns (right or left) per meter d.-68 filaments300 turns (right or left) per meter Mi-perles are yarns composed of two or more strands twisted together, the individual strands being continuous strands which have received a primary twist, either to the right or left, as in the case of voilines, and the component strands being twisted together with a number of turns lessthan that of the primary twist and in a direction or sense opposite that of the primary twist. For mi-perles, starting with crimped filament yarn having only the producers twist, it has been found that, depending on the weight of the yarn and number of component filaments, the twists given the yarn for the best results are represented by the following:

M i-perles Two 70 d.each 34 filaments:-

Individual 625 turns right per meter Together 550 turns left per meter Two 100 d.-each 34 filaments:

Individual 600 turns right per meter Together 500 turns left per meter Two 140 d.-each 68 filaments:

Individual 575 turns right per meter Together 450 turns left per meter Ovales are yarns composed of two or more strands twisted together, the individual strands being continuous strands without a primary twist and the component strands being twisted together with a low twist either to the right or left. For ovales, starting with a crimped filament yarn having only the producers twist, depending on the weight of the yarn and number of component filaments, the twists giventhe yarn for the best results are 3 represented by the following:

Ovales Two 70 d.-each 34 filaments-50 turns left'per meter Two 100 d.each 34 filaments-435 turns left per meter Two 140 d.--each 68 filaments-225 turns left per meter The lubrication of looms of this sort is usually accomplished by coating the loom parts with graphite. The yarn picks up the graphite by reason of a charge of static electricity which it acquires from the friction. It isnecessary that the yarn be entirely freed of this graphite and a suitable sizing is used to protect the yarn. Polyvinyl alcohol has heretofore been used as a sizing which has been satisfactory for the standard yarns used in the lace industry, but for the making of lace from crimped yarns, such sizing is not satisfactory since it leaves the yarn too stiff and without the property of lateral expansion.

It has been found that polyacrylic acid is antigraphite and satisfactory as a sizing for the crimped yarn to be used in the lace industry, as it leaves the yarn sufficiently pliable to produce lace of desirable texture with requisite bulking to give suitable appearance and coverage.

This invention therefore contemplates the use of polyacrylic acid as a sizing for the crimped yarns twisted as above described. Specifically, it has been found that the best results are obtained by the use of polyacrylic acid of about 25% concentration and applied to the yarn in an amount of about 2 /z% to 4% by weight of the weight of the yarn.

At the final winding, the sizing is lubricated with a coating of oil and for this it is necessary to use an oil which emulsifics easily and which has an iodine index of zero. The weight of the oil should be from 1% to 2% of the weight of the yarn.

The nylon yarn so prepared for the lace making industry is wound on to a conical or cylindrical tube after having been cleaned of imperfections.

Yarns treated in accordance with this invention have a covering capacity which is approximately 50% greater than that of ordinary nylon and thus there is obtained economy of material due to the increased covering capacity and an improvement in texture of the lace. Very satisfactory results have been obtained with lingerie lace and on guimpes with a background of fine yarns.

It is desirable for lace to use the treated yarn in substantially the same measurements as has been customary with ordinary nylon yarns, preferably using voilines for guimpes and mi-perles for embroidering or edging. Also the mi-perles' can be employed either in novelties or wool lace." Ovales can be used with wool lace if the low twist does. not cause hooking or catching. In all cases steaming should precede the dyeing to improve the bulking of the yarn. After dyeing, it is also important to control the amount of finish.

a of twist and twisting the crimped filaments together to a predetermined state of bulk and looseness, then combining a plurality of such component strands and twisting them together with less turns per unit of length than those of the component strands and in the direction opposite thereto, setting the yarn in said twisted state, and finally sizing the yarn.

2. The method of forming a plurality of yarns each;

of different denier for use in lace weaving consisting in combining for each yarn a plurality of crimped individual filaments substantially free of twist, twisting the combined crimped filaments of each yarn together to a predetermined state of bulk and looseness, the relative number of twists per unit of length imparted to the several yarns being in inverse relation to the denier measurement of the yarns, setting the yarns in said twisted state, and finally sizing the yarns.

3. The method of forming a plurality of yarns each of different denier for use in lace weaving consisting in first forming for eachyarn a plurality of component strands by combining for each strand a plurality of crimped individual filaments which are substantially free of twist and twisting the combined crimped filaments together to a predetermined state of bulk and looseness, the denier of the component strands of each yarn being the same and different from those of the strands of the other yarns and the relative number of twists per unit of length imparted to the strands of the several yarns being in inverse relationto the denier measurement of the respective strands, then combining a plurality of similar component strands so formed and twisting them together for each yarn with less turns per unit of length than the turns of the component strands of the respective yarns and in the direction opposite thereto, setting the yarn in said twisted state, and finally sizing the yarn.

4. The yarn formed by the method of claim 1.

5. The yarn formed by the method of claim 2.

6. The yarn formed by the method of claim 3.

References Cited in the file of this patent UNITED STATES PATENTS 2,810,949 Silver Oct. 29, 1957 2,826,515 Rickert et al Mar. 11, 1958 FOREIGN PATENTS 482,425 Great Britain Mar. 29, 1938 743,906 Great Britain Jan. 25, 1956 

1. THE METHOD OF FORMING YARNS FOR USE IN LACE WEAVING CONSISTING IN FIRST FORMING A PLURALITY OF COMPONENT STRANDS BY COMBINING FOR EACH STRAD A PLURALITY OF CRIMPED INDIVIDUAL FILAMENTS WHICH ARE SUBSTANTIALLY FREE OF TWIST AND TWISTING THE CRIMPED FILAMENTS TOGETHER TO A PREDETERMINED STATE OF BULK AND LOOSENESS, THEN COMBINING A PLURALITY OF SUCH COMPONENT STRANDS AND TWISTING THEM TOGETHER WITH LESS TURNS PER UNIT OF LENGTH THAN THOSE OF THE COMPONENT STRANDS AND IN THE DIRECTION OPPOSITE THERETO, SETTING THE YARN IN SAID TWISTED STATE, AND FINALLY SIZING THE YARN. 